fix(mcp): scope cortex_intelligence by explicit project param

[jessekemp1]

Summary

cortex_intelligence could not be scoped to a project, so every project-unscoped query was silently answered against the cortex project. A pre-flight question about a different project (e.g. "what cloud does Interac run on?") returned 0.0 confidence with no relevant context — not because the data was missing, but because the query never searched the right project.

This adds an optional project parameter to the tool and forwards it to the bridge.

Root cause

Two independent hardcoded-to-cortex defaults sit on the query path:

1. mcp_server.py — cortex_intelligence(query, query_type) exposed no project param and POSTed only {request, domain, query_type} to /intelligence/query.
2. api/bridge_endpoint.py — IntelligenceQuery.project has default="cortex", so the omitted field became "cortex" before the handler ran.
3. bridge.py:384 — even when project is empty, _detect_current_project() runs git rev-parse --show-toplevel with cwd=self.root_dir (the bridge daemon's own directory, always the cortex repo) and falls back to a hardcoded return "cortex".

The bridge is one long-lived daemon serving every Claude session across all projects; it has no channel to learn the caller's working context, so it cannot infer the project on its own. The only reliable signal is an explicit project from the caller.

Fix

• Add an optional project: str = "" arg to cortex_intelligence.
• Forward it in the request body when set; omit it when empty so existing auto-detect/back-compat behavior is preserved.

This mirrors the sibling tools (cortex_taskboard, cortex_outcomes, cortex_plan_create, and the cortex-dbx recall_similar / record_decision) that already take an explicit project.

Verification

Against the live bridge:

Request	Scoped to
no project	cortex (the bug)
project="interac"	interac (fixed)

Unit logic (forwarded when provided, omitted when empty) confirmed directly and covered by a new regression test in tests/test_mcp_research_tools.py::TestCortexIntelligenceProjectScope. Tool count is unchanged, so existing registration tests stay green.

Why here and not cortex-dbx

cortex_intelligence, the bridge, and _detect_current_project() live only in this repo. cortex-dbx is a separate Databricks App whose MCP tools already take an explicit project, so it never had this bug.

Recommended follow-ups (not in this PR)

• Change IntelligenceQuery.project default from "cortex" to empty, and make _detect_current_project()'s fallback project-agnostic (search all projects) so an unscoped query returns an honest cross-project result instead of silently biasing to cortex.
• Wire the /scope skill into /intelligence/query so a session can set its active project.

This pull request and its description were written by Isaac.